Page "Hair" Paragraph 51

The latter hypothesis seems the more plausible evolution determinant as the surface area of the head is minute compared to the remainder of the body, thus the energy required in producing long hair for the express purpose of " optical " amplification of UV light reflected from the snow seems counterproductive ( however, it's very likely that the trait was sustained due to a nuanced combination of multiple influences, given that human hunting-skills and ingenuity were such by 50, 000 years ago that said benefits in terms of ' comfort ' could have alternatively been derived from constructing head and ear warmers of fur from prey, etc .).

Scientists point to the fact that straight hair found in many ethnic groups is denser as well and has a greater ability to " show " as it does not coil, hence providing more warmth as the likely deterministic factor for the evolution of straight long hair.

Some scientists argue that since the head and appendages are the greatest areas for heat loss from the body, the ability to grow long hair on the crown of the head as well as the face provides a distinct advantage in a cold climate.

Since the main sensory organs are anatomically located on the head, long hair provides the necessary warmth and protection in a cold climate that allows the use of these organs by exposing them to the elements to " sense ", in for example a hunt, yet still providing necessary warmth and protection to sustain prolonged exposure.

It may be argued, therefore, that the ability to grow long, straight, densely packed hair provides a distinct evolutionary advantage in cold climate ; however, it would be a distinct disadvantage in a hot climate, when compared to loosely packed, spongy, closely cropped hair.